Resealable container



May 3, 1966 J. P. REPKO 3,249,288

RESEALABLE CONTAINER Filed Aug. 24, 1964 2 Sheets-Sheet 1 INVENTOR JOHNF? REPKO Pw WgW ATTOR EY May 3, 1966 J. P. REPKO RESEALABLE CONTAINER 2Sheets-Sheet 2 Filed Aug. 24, 1964 INVENTOR JOHN P REPKO BY %JlM iATTORNE ,heat sealable, thermoplastic resin surface.

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' 3,249,288 RESEALABLE CONTAINER John P. Repko, Beaverton, Mich,assignor to The Dow Chemical Company, Midland, Mich., a corporation ofDelaware Filed Aug. 24, 1964, Ser. No. 391,683 8 Claims. (Cl. 229-66)contain gusscts for easier accommodation of the product to be packaged.These containers may be provided with an opening means such as a tearstring. In many instances when certain types of gases are used as aflush 'to assure content protection even in completely sealed packagesor where vacuums are drawn the tear string has proved to be impracticalto use as an opening device be- ,cause of a wicking action (through thestring) which allowed loss of gases and/or vacuum causing shorted shelflife and in instances complete spoilage of contents. Therefore suchcontainers are generally opened by the use of a foreign implement suchas a knife or scissors. Frequently the opening of the container is donein such a manner as to make further use of the container impractical. Inmany instances the contents of the con ltainer are only partially usedand it is desirable, therefore, to provide opening means which do notimpair the further use of the container, and, in addition, to provide a[means'for rescaling the package to protect the contents from theatmosphere which may cause the contents to lose flavor or even spoil.

It is therefore the object of the present invention to provide acontainer which seals, hermetically, the con- It is another object toprovide a hermetically sealed container containing an, easy openingdevice that is considered to be a direct part of the Web of materialrequiring no foreign implements for opening. It is still another objectof the present invention to provide an easy opening device for a pouchor bag type container which can be used to rescal the container forfurther storage of thecontents. Other objects will become apparenthereinafter.

The objects of the present invention are accomplished by a generallyflat container in which at least one side comprises a flexible web inwhich at least the inner surface of said side -compriscsa heat scalablethermoplastic resin, a perforated tear line in said web extending todifferent edges of the container formed by said web in a manner capableof forming an opening for the removal of the. container contents, saidperforated tear line being sealed off a heat scalable thermoplasticresin tape, a flap capable of being folded down over and covering saidperforated tear line, said flap being folded onto the container andsealed to the edges of said web, said container assemblage containing anadhesive area capable of sealing said flap to said web when folded oversaid perforated tear line and a cover means removably applied to saidadhesive area.

Reference is now made to the drawings for a more detailed description ofthe invention in which:

FIGURE 1 is a schematic illustration of the manner in which the easyopening and rescaling device of the present invention may beincorporated into a container production line;

United States Patent rations.

ice I FIGURE 2 is a perspective-like view of a container embodying theprinciples of the invention;

FIGURE 3 is a perspective-like view of a container embodying theprinciples of the invention being opened;

and

FIGURE 4 is a perspective-like view of a modified container embodyingthe principles of the invention on opening and rescaling.

Referring now to FIGURE 1, a web 10 from roll stock 11 having a heatscalable thermoplastic resin surface 12 is contacted with perforatingwheel 13. which causes a perforated tear line 14 to be-formed in the web10. The nature of the perforation introduced is not critical and may bein any shape, i.e., a continuous row of round holes, square holes,slits, and/or cuts punched at varying intervals and scoring; thefunction of such perforation being, of course, to assist in the tearingof the web in the line of the perforation. The web is then contactedwith a heat scalable tape 15 from spool 16 in a manner such that itcovers the perforated tear line 14. The width of the tape is notcritical but should be sufficiently wide enough to seal'off theperforations. Heated rollers 17 and 18 seal the tape to the heatscalable surface of the web thereby sealing off the perforation.Although it is not essential, the heat scalable tape is preferablyscaled to the heat scalable surface of thewcb. Where the web consists ofa thermoplastic resin, the tape can be readily sealed to either surface.

The seal is permitted to cool as the web continues in the machinedirection. -A blower 25 may be employed to direct a continuous flow ofcool air on the sealed perfo- Instead of air cooling, water cooling maybe employed to reduce cooling periods.

The flap may be formed .in various ways. Thus the web containing thesealed perforations may be directly used in a filling station, the flapbeing formed by bringing the two web edges together around the contentsand heat sealing the web edges together as illustrated in FIG- URE 2.The flap can be then folded over in either direction, i.e., over thesealed perforations or folded back on to the container parallel withsaid perforations. The

flap when folded back may be held secure by the end seals which completethe sealed container. The double coated sensitive tape with itsprotective covering can then be aflixed on either the flap or adjacentto and parallel with the sealed perforations.

Another method of forming the fiap comprises contacting the cooled webin FIGURE 1 with another wider tape 19 supplied from spool 20. This flaptape is preferably made from a heat sealablethermoplastic resin althoughany tape containing at least one heat scalable surface may be employed.The tape should be wide enough, on sealing of a strip of the tape to theweb, to cover the perforated tear line and extend a small distancebeyond the tear line. The tape is positioned by roll 21 to fit over thesealed perforated tear line 14. If desired, the roll 21 may be heated topreheat the tape 19. A narrow strip 22 of the tape, which is positionedon the web with a heat sealable surface contacting the web, is thensealed to the web by heated roll 23 to form the flap for the container.Platform 24 provides the necessary backing plate to allow suflicientpressurc'to be applied by rolls 21 and 23 to accomplish the correctpositioning and sealing. The seal is parallel to, but set off from, theperforation. This method can be used when the container is fabricatedfrom one or two separate webs of material. The pressuresensitive, doublecoated tape with protective covering can be applied as previouslymentioned.

The web is then cut or folded and heat sealed to form the containerillustrated in FIGURES 2 to 4. Other means of applying the perforationsand sealing the perforations will be apparent to those skilled in theart.

FIGURE 2 shows an open container with the unsealed flap 30, obtained byfolding of the web, in the upright position parallel to but set off fromthe sealed perforated tear line 31, extending the width of thecontainer, wherein the perforations have been sealed off by the tape'32. The surface of the container adjacent to the seal has been providedwith an adhesive area or pressure sensitive tape 34 capable ofcontacting flap 30, when such is folded over the sealed perforated tearline 31. The adhesive area may extend the entire length of the areacovered by the flap 30 or just part thereof as illustrated. It isfurther possible to provide several smaller adhesive areas instead ofone continuous one.

FIGURE 3 shows substantially the container of FIG- URE 2, which has nowbeen heat sealed, being opened. The flap 30 has been folded back ontothe container and the. two sides and the-flap have been scaled togetherto form fin-type seals 35 and 36. Adhesive area 34 has been applied tothe flap 30, rather than to the container as illustrated in FIGURE 2,and covered with a removable strip of tape. The user of the containerhas torn part of the perforated, sealed tear line 31 by lifting up onthe flap and pressing down on the container area opposite to that beinglifted and has formed opening 37. Instead of having the flap folded backonto the container as illustrated inFIGURE 3 it will be apparent thatthe same result is obtained when the flap is folded over-theperforations as illustrated in FIGURE 4 and then sealed at the edges. 7

In FIGURE 4, a modified container, in which all four edges have afiu-type heat seal 38 is shown after opening and rescaling. Flap 30 hasbeen loosened from the edges, folded over the opened perforated tearline 31, and sealed to the container by means of adhesive strip 34. Heatseal 39 results from the application of the flap to the web asillustrated in FIGURE 1.

The web employed in the manufacture of the containers having the easyopening and rescaling device hereinabove described canbe formed of oneor more polymeric substance such as a polyolefin and particularlypolyethylene or polypropylene, a polyvinyl halide, a polyvinylidenehalide and copolymers and interpolymers thereof, or may be formed bycoating a substratesuch as a cellophane, paper, foil, or polyester webwith one of the aforesaid polymeric materials on one or both of thesurfaces of such webs. The heat sealable thermoplastic tape employed toseal off the perforated tearline is generally thinner than thethermoplastic web material or the coated web material.

Preferred materials employed in the construction of the describedcontainers are polyolefin webs and polyolefin coated transparent webs onsuch materials as cellophane, saran, and polyester; of the polyolefins,polyethylene is preferred.

Although the present invention is described in terms of heat sealing,since such is preferably used, the various components of the containermay also be sealed by the use of an appropriate adhesive. The adhesivematerial used to seal the flap to the container is of the type whichretains its adhesive powers even after exposure to the atmosphere, andwhich will stick to another surface merely by the application ofpressure. The container has been described in terms of side wallscontaining two flexible webs. Again it is possible to vary thisconstruction without affecting the use and advantages of the easyopening and rescaling device of the present invention. Thus one of thecontainer sides may be a semi-rigid or rigid sheet made of the same or adifferent material than the flexible covering Web containing the easyopening and resealing device of the present invention. Othercombinations and container constructions in which the present inventioncan be employed will be apparent to those skilled in the art.

It is to be understood that the foregoing description of the inventionis not intended to limit the scope thereof except as defined in theappended claims.

I claim:

1. A container having at least one side made of a flexible web in whichat least the inner surface of said side comprises a heat sealablethermoplastic resin, a perforated tear line in said web extending todifferent edges of the container formed by said web in a manner capableof forming an opening for the removal of the container contents, saidperforated tear line being sealed off by a heat sealable thermoplasticresintape, a flap capable of being folded down over and covering saidperforated tear line,

said flap being folded onto the container, and sealed to the edges ofsaid web, said container assemblage containing an adhesive area capableof sealing said flap to said web when folded over said perforated tearline and a cover means removably applied to said adhesive area.

2.The container of claim 1 wherein said heat sealable thermoplasticresin tape is sealed to the surface of the web containing thethermoplastic resin.

3. The container of claim 1 wherein the container comprises twosuperimposed flexible sheets having at least the inner surface of saidsheets comprising a heat sealable thermoplastic resin.

4. The container of claim 1 wherein the flap is sealed to the outersurface of the web'in a line parallel to the perforated tear line.

5. The container of claim 3 wherein the sheets comprise a heat sealablethermoplastic resin.

, 6. A generally flat, rectangular container formed from twosuperimposed flexible sheets wherein each sheet contains at least oneheat sealable thermoplastic resin surface, said resin surfaces formingthe inner wall of said container, said container having at least twoopposing fin-type edge seals, a perforated tear line in one of saidsheets extending to opposite fin-type edge seals, said perforated tearline being sealed off by a thermoplastic resin tape along its entirelength, said sheet further containing a flap extending across said sheetbetween said fin-type edge seals in a line parallel to said perforatedtear line, said fia-p having a width sufficient to cover said perforatedtear line and being folded onto the container and sealed to saidfin-type edge seals, said container assemblage containing an adhesivearea capable of sealing said flap to said container when folded over thesaid perforated tear line and a cover means removably applied to saidadhesive area.

7. The container of claim 6 wherein the said thermoplastic resin tape issealed to the inner wall of said container.

8. The container of claim 7 wherein the sheets comprise a heat sealablethermoplastic resin.

References Cited by the Examiner GEORGE O. RALSTON, Primary Examiner.

1. A CONTAINER HAVING AT LEAST ONE SIDE MADE OF A FLEXIBLE WEB IN WHICHAT LEAST THE INNER SURFACE OF SAID SIDE COMPRISES A HEAT SEALABLETHERMOPLASTIC RESIN, A PERFORATED TEAR LINE IN SAID WEB EXTENDING TODIFFERENT EDGES OF THE CONTAINER FORMED BY SAID WEB IN A MANNER CAPABLEOF FORMINGS AN OPENING FOR THE REMOVAL OF THE CONTAINER CONTENTS, SAIDPERFORATED TEAR LINE BEING SEALED OFF BY A HEAT SEALABLE THERMOPLASTICRESIN TAPE, A FLAP CAPABLE OF BEING